title: Insulin-like growth factors, their binding proteins, and fetal macrosomia in offspring of nondiabetic pregnant women.
abstract: The Objective of this paper is to determine the relation between fetal macrosomia in offspring of nondiabetic women, and the levels of insulin-like growth factors (IGF-I, IGF-II), insulin growth factor binding protein-3 (IGFBP-3) and insulin, in maternal and neonatal compartments. Serum samples were obtained from normal pregnant women (n = 60) and their neonates (n = 60) between 37-41 weeks' gestation (mean 39 +/- 9). Neonates were categorized as appropriate for gestational age (AGA; 10th-90th percentile; n = 20), and large for gestational age (LGA; >90th percentile; n = 40). Maternal and neonatal serum samples were analyzed for levels of IGF-I, IGF-II, IGFBP-3 and insulin, by specific radioimmunoassays (RIAs). Serum levels were correlated with birth weight. The mean birth weight of the AGA group was 3296 +/- 500 g versus 4201 +/- 300 g for the LGA group (p <0.0001). Cord blood IGF-I was statistically higher in LGA group than in the AGA infants, (139 +/- 67 ng/mL and 80 +/- 32 ng/mL, respectively; p <0.0001). There was no correlation between maternal IGF-I serum levels and birth weight (363 +/- 131 in the AGA vs. 308 +/- 158 in the LGA group). IGF-II in maternal and cord blood did not correlate with fetal weight. Cord blood IGFBP-3 was significantly higher in the LGA group (1.1 +/- 0.07 microg/mL) than in the AGA group (0.96 +/- 0.05 microg/mL; p < 0.05). Maternal insulin levels were similar between the two groups. Neonatal insulin levels were higher in the LGA group (18 +/- microU/mL) as compared to the AGA group (16 +/- microU/mL), however, this difference did not reach statistical significance. Fetal cord blood levels of IGF-I and IGFBP-3 are directly correlated with the birth weight of large for gestational age fetuses. These data suggest that the somatotropic axis plays a role in fetal growth. Additionally, insulin growth factor-1 appears to be an in utero growth promoter in the development of fetal macrosomia in infants of nondiabetic women.
authors.affiliation: Department of Obstetrics and Gynecology, Soroka Medical Center, Ben-Gurion University, Beer-Sheva, Israel.
authors.forename: A
authors.initials: A
authors.lastname: Wiznitzer
authors.forename: E A
authors.initials: EA
authors.lastname: Reece
authors.forename: C
authors.initials: C
authors.lastname: Homko
authors.forename: B
authors.initials: B
authors.lastname: Furman
authors.forename: M
authors.initials: M
authors.lastname: Mazor
authors.forename: J
authors.initials: J
authors.lastname: Levy
mesh_terms: D000328:Adult; D001724:Birth Weight / Q000502:physiology; D005260:Female; D005312:Fetal Blood / Q000737:chemistry; D005320:Fetal Macrosomia / Q000097:blood / Q000209:etiology*; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D007328:Insulin / Q000097:blood / Q000502:physiology*; D018972:Insulin-Like Growth Factor Binding Protein 3 / Q000097:blood / Q000502:physiology*; D007334:Insulin-Like Growth Factor I / Q000032:analysis / Q000502:physiology*; D007335:Insulin-Like Growth Factor II / Q000032:analysis / Q000502:physiology*; D011247:Pregnancy; D011863:Radioimmunoassay
chemical_list: D007328:Insulin; D018972:Insulin-Like Growth Factor Binding Protein 3; D007334:Insulin-Like Growth Factor I; D007335:Insulin-Like Growth Factor II